Rotary swivel having improved means for relieving pressure on the packing



Nov. 15,1949 GER. TREMOLADA 2,487,905

ROTARY SWIVEL HAVING IMPROVED MEANS FOR RELIEVING PRESSURE ON THE PACKING 3 Sheets-Sheet l Filed. March 23, 1945 INVENTOR. sueusgmo R. TREMOLADA ATTORNEY Nov. 15, 1949 G. R. TREMOLADA 2,487,905

- ROTARY SWIVEL HAVING IMPROVED MEANS-FOR RELIEVING PRESSURE on THE PACKING Filed. March 23, 1945 3 Sheets-Sheet 2 3| x as 32 INVENTOR. QUGLIELMO R. TREMQLADA ATTORNEY Nov. 15, 1949 v G. R. TREMOLADA 2,437,905

ROTARY SWIVEL HAVING IMPROVED MEANS FOR RELIEVING PRESSURE ON THE PACKING Filed. Marbh 2:5, 1945 s Sheets-Sheet s INVENTOR. GUGLI ELMO R. TREMOLADA BY f ATTOR NEY Patented Nov. 15, 1949 ROTARY SWIVEL HAVING IMPROVED MEANS FOR RELIEVING PRESSURE ON THE PACK- ING . Guglielmo R. Tremolada, LomAngeles, CaliL, as-

' slgnor to Emsco fornia Derrick & Equipment Company, Los Angeles, Calif.,

a corporation of Call- Application March- 23, 1945, Serial No. 584.371 7 Claims. (Cl. 285-97.1)'

My invention relates in general to rotary swivels such as used in rotary well drilling to support a string of drill pipe, and relates in particular to an improvement in means for conducting fluid, such as drilling mud, from the stationary to therotatable part of the swivel.

In rotary swivels the mud is conducted through a mud inlet member, commonly referred to as the gooseneck, to a passage in the rotating body of the swivel, which passage communicates with the upper end of the string of the drill pipe, with a packing device for preventing escape of mud from the joint which exists between the relatively non-rotating parts of the swivel and the rotating part of the swivel. Owing to severe working conditions--including the high pressure applied to the mudthese packed joints of rotary swivels give considerable trouble due to rapid failure of the packing. It is an object of my present invention to provide a rotary swivel having a packed joint which will give satisfactory service for relatively compared to the service now rendered packing means of rotary swivels.

It is an object of the invention to provide a rotary swivel having an eificient packing means but which has means for reducing the fluid pressure in the aperture of the packed joint, thereby reducing the pressure against the packing and decrease the rate of wear of the packing.

A further object of the invention is to provide a simple wash pipe arrangement which cooperates with other elements in a rotary swivel to produce a reduction in the pressure against the packing, certain of these parts which are worn by the mud flow being so related to the parts which cooperate therewith as to be readily and economically replaced.

An object of the invention is to provide a rotary swivel having a mud inlet passage leading to a packed joint through which the mud inlet passage communicates with the mud outlet passage of the rotary swivel, this mud inlet passage being reduced in diameter adjacent the annular aperture of'the packed joint so as to produce an increasein the velocity of the mud flow which will accomplish a reduction in fluid pressure in the joint aperture and thereby reduce the fluid pressure which must be held by the packing.

A further object of the invention is to provide in a rotary swivel a cooperation of parts contributing to ease in removal and replacement of the wear receiving parts of the improved mud joint and the pressure reducing means associated with the same.

Further objects and advantages of the invention will be brought out in the following part of the specification.

Referring to the drawings which are for illustrative purposes only.

by the long periods of time as Fig. 1 is a partly sectioned elevational view of a swivel embodying my invention. I

Fig. 2 is an enlarged fragmentary section showing the upper part of the swivel.

Fig. 3 is a view showing certain parts of the swivel separated, to illustrate the manner of removal and replacement of wear receiving parts.

Fig. 4 is an enlarged fragmentary sectional view of an alternative form of my invention.

Fig. 5 is a fragmentary view showing the manner in which parts are replaced in the form of the invention disclosed in Fig. 4.

In Fig. 1 I show a rotary swivel comprising a shell l0 and a body supported in the shell for relative rotation by radial bearings l2 and thrust bearings iii. The body H has an axial opening I! extending from top to bottom thereof, this opening It being referred to hereinafter as the outlet mud passage of the rotary swivel, for the reason that it serves asv a means for conveying mud to the upper endof a string 'of drill pipe which may be connected to the lower end of the body by a fitting l5. The shell i0 is shown with trunilaions I6 for. attachment to the shell of a ball I.

The shell I has upwardly converging walls It which connect at their upper ends to a horizontal supporting wall I9, so called for the reason that this wall I9 provides a support for a gooseneck 20 and for a wash pipe 2| which extends downwardly from the supporting wall is toward the upper end of the body ll.

As shown to enlarged scale in Fig. 2, the supporting wvall I! has an opening 22 which is counterbored in alignment with the mud outlet passage M of the body II, to receive an annular rubber wall 23 which is molded upon the upper end of the wash pipe 2|, thereby supporting the wash pipe 2| in its operative position. The annular rubber body 23 provides a yieldable support for the wash pipe 2| to compensate for all disalignments which may exist between the opening 22 and the parts which are carried by the body so as to engage the wash pipe 2| The lower end of the wash pipe 2| confronts the upper end of the body and between the members 2| and M an annular joint aperture 24 is formed, this joint aperture 24 being sealed against escape of mud therethroug-h by packing means 25 comprising a hollow fitting 26 which is threaded onto the upper end of the body II and carries therein an assembly of packing rings 21 in engagement with the lower portion of the outer face of the wash pipe 2|. p I

The gooseneck 20 defines a mud inlet passage 28 and the wash pipe2| defines a continuation of the mud inlet passage 28 through which the rotary mud is conducted to the upper end of the mud outlet passage ll from the rotary hose 2!,

which is ordinarily employed in the drilling of wells by the rotary method. One of the features oiv the invention resides in the restriction or diametral reduction of the outlet end 30 of the mud inlet passage 23 so as to increase the velocity of the mud flow as it passes across the jointaper ture 24, thereby reducing the fluid pressure in the joint aperture 24 and correspondingly reducing the pressure applied to the rings 21 of the packing means 25. The outlet end 30 of the passage 23 is defined by an annular shoulder 3|, which forms part of the wash pipe 2 I, and which is of smaller diameter than the upper or. inlet end 32 of the passage l4. As the mud flow passes across this shoulder 3| and enters the passage l4, a pressure drop is produced in the annular joint aperture 24.

In the showing in Fig. 2 the mud inlet passage 23 is gradually reduced in diameter from a point which is remote from the joint aperture 24, to a point adjacent the .mud aperture 24. The mud inlet passage 28 has its largest diameter at the inlet end 33 of the gooseneck 20 mi has its smallest diameter at the shoulder 3|. In view of this, there is an increase in the velocity of the mud fiow from the time it enters the gooseneck 20 until the joint aperture 24 is reached, and then beyond, or below, the joint aperture 24 the velocity of the mud flow is reduced. As shown in Figs. 1 and 2, the upper end of the mud outlet passage I4 is gradually diametrally enlarged until a point 34 spaced from the joint aperture 24 is reached, the passage |4 being thereafter of substantially constant diameter. During drilling operations the body H and the packing means 25 rotate relatively to the wash pipe 2| and the rings 21 slide upon the surface of the wash pipe 2|. The reduction in pressure in the annular joint aperture 24, produced in the manner described in the foregoing, in turn reduces the pressure of the packing rings 21 against the surface of the wash pipe 2|. This reduction in pressure reduces the rate of wear between the packing rings 21 and the wash pipe 2| and correspondingly extends the life of these parts. An important element of the invention to be here considered is that the extension of the life of the wearing parts 2| and 21 is not in direct proportion to the reduction in pressure in the joint aperture, but the extension of the life of these wearing parts is proportionately considerably greater than the pressure reduction in the aperture 24.

The gooseneck 20 is secured to the supporting wall H! by bolts 35 which permit removal of the gooseneck 20 from the wall Is as shown in Fig. 3, thereby exposing the upper end of the opening 22 so that the wash pipe 2| may be lifted upwardly through the opening 22 and replaced by a. new or reconditioned wash pipe when wear makes this necessary. When the wash pipe 2| is lifted, as shown in Fig. 3, the fitting 26 of the packing means 25 may be unscrewed from the upper end of the body II and removed so that the assembly of packing rings 21 therein may be renewed.

In the form of the invention shown in Fig. 4, the wash pipe 2| is fixed on the upper end of the body so as to rotate therewith and the upper end of the wash pipe 2| rotates within an assembly of packing rings 21 which are supported within a shell or fitting 26' which is carried by the supporting wall IS, the upper end of -the shell 25' being flanged and the opening 22' of the supporting wall l9 being of such diameter as to accommodate passage therethrough of the lower portion of the shell 26' and of the internally threaded attachment ring 31 4 by which the wash pipe 2| is secured to the upper end 01' the body The upper portion of the wash pipe 2| has thereon a layer of hard, wear-resisting material 33, such as glass, for example, to engage the inwardly exposed edges of the packing rings 21'.

The supporting wall I! is extended laterally and is integral with a tubular mud inlet member 40 which is rigidly held in place by reason of its connection to the supporting wall l9 and its connection to the shell ll) of the swivel by a web 4|. The rotary hose 42 is connected to the lower end of the mud inlet member 40 and the downward pull, due to the weight of the rotary hose 42, is taken directly by the inlet member 40. In this form of the invention a gooseneck member 20' is provided which is adapted to be bolted against the upper face of the supporting wall i3, this gooseneck member 20' having therein a mud inlet passage 28', the outer end of which communicates with the upper end of the passage 40' of the member 4|) and'the other end of which is aligned with the wash pipe 2|.

The outlet end of the mud inlet passage 28' is defined by an insert 43 which is threaded into a recess 44 in the member 20', and this insert or nipple 43 defines a nozzle opening 45 of reduced diameter in alignment with the upper end of the wash pipe 2| The insert 44 has at its lower end a shoulder 43 which is smaller than the upper end of the passage |4' oi. the wash pipe 2|, and between the upper end of the wash pipe 2| and the lower end of the insert 43 there is an'annular joint aperture 24' which communicates with the upper end of the assembly of packing rings 21. The increase in velocity of the mud flow as it passes from the opening 45 of the insert 43, and its characteristic action, produces a pressure reduction in the joint aperture 24'. The mud inlet passage 28', which is regarded as including the opening or passage 45 of theinsert 43, is reduced from a maximum diameter remote from the joint aperture 24' to a minimum diameter adjacent the joint aperture 24', this diametral reduction of the passage 23' being gradual and producing the desired gradual increase in the velocity of the mud fiow as the shoulder 46 of the insert 43 is approached. The passage H of the wash pipe 2| is gradually diametrally increased as it progresses downwardly from the joint aperture ..24' and the lower end of the passape l4 has a diameter substantially the, same as that of the mud outlet passage H of the body ll, of which the passage I4 is an upward extension.

In the form of the invention shown in Fig. 4, all of the parts subjected to wear are readily replaceable. The insert 43, although it may be made 01' hard material, is subject to the wear produced by the high velocity flow of mud. The upper portion of the wash pipe 2| is also exposed to a relatively high velocity flow of mud. At suitable intervals, the parts 2 and 43 may be replaced. In Fig. 5 the manner of disassembly of the upper portion of the swivel assembly is shown. The gooseneck member 20 may be removed without necessity of disconnecting the rotary hose 42, thereby exposing the opening 22' in the supporting member 8'. The holding ring 31, Fig. 4, may be unscrewed from the upper end of the body whereupon the wash pipe 2 the shell 26', the assembly of packing rings 21' therein, and the holding ring 31 may be lifted through the opening 22'.. Also, when the gooseneck memshell and a body in rotatable relation, said body having a wall forming a mud passage and said shell having a mud passage, said passages being disposed in end to end relation so that a joint aperture is formed therebetween, said joint aperture having a mouth exposed to the flow of mud through said passages, and said passages being reduced in diameter adjacent to theymouth of said joint aperture so as to increase the velocity of the mud flow across the mouth of said joint aperture and thereby produce a reduction in the pressure of mud in said joint aperture; and packing means for said joint'aperture for sealing the same. v

2. In a rotary swivel, the combination of: a shell and a body in rotatable relation, said body having a wall forming a mud passage. and said shell having a mud passage, said passages bein disposed in end to "end relation so that a joint aperture is formed therebetween, said joint aperture having a mouth exposed to the flow of mud through said passages, said passages each bein gradually reduced from amaximum diameter remote from the mouth of said joint aperture to a minimum diameter adjacent the mouth of said joint aperture so as to increase the velocity oi the mud flow across the mouth of said joint aperture and thereby produce a reduction in the w shell and a body in rotatable relation, said body having a wall forming a mud outlet passage;

; Walls forming a gooseneck supported by, said shell and a wash pipe aligned with said mud passage of said body .so as to form'between said wash pipe and said passage a joint aperture having a mouth exposed to the flow of mud through said passage means, said gooseneck and said joint aperture to a minimum diameter adpressure of mud in said joint. aperture; and

packing means for said joint aperture for sealoutlet passage adapted to be connected tothe drill pipe so as to deliver the mud thereto, said passages being disposed in end to end relation so that a joint aperture is formed therebetweenhaving a mouth exposed to the flow of mud through said passage means, and said mud inlet passage being gradually reduced from a relatively large diameter remote from the mouth oisaid joint apertureto a relatively small diameter adjacent the mouth of said joint aperture so as to increase the velocity ofthe mud flow across the mouth of said joint aperture and thereby produce a reduction in pressure of the mud in said joint aperture; and packing means for said joint aperture for sealing the same; w

4. In a rotary swivel, the combination of: a shell and a body in rotatable relation, said body having a wall forming a mud passage; walls forming, a gooseneck supported by said shell and a wash pipe aligned with said mud passage of said body so as to form between said wash pipe and said passage a joint aperture having a mouth exposed to the flow of mud through said passage means, said gooseneck and said wash pipe being so formed as to define a mud inlet passage which .is decreased in diameter adjacent the mouth of 5. In a rotary swivel. the combination of: a

jacent the mouth of said joint aperture so that there will be an increase in velocity of the mud flow as it passes across the mouth of said joint aperture and a consequent reduction in the fluid pressure in said joint aperture; and packing means for said joint aperture.

6. In a rotary swivel, the combination comprising: a tubular stationary part; a tubular rotary part, said parts being positioned in endto-end relation with their confronting ends axially aligned and spaced apart to form an annular aperture; a hollow member carried by one of said parts extending over the adjacent 'end of the other part and cooperating with its adjacent'exterior surface to form an annular packing receiving space in communication with said annular aperture; a packing within said packing ,space; and interior walls within said parts re? spectively forming fluid passageways of gradually decreasing diameter with their smallest diameters at opposite sides of said annular aperture,

whereby fluid flow through said passageways acts through said annular aperture with reduced pressure upon said packing.

'7. In a rotary swivel, the combination comprising: a tubular stationary part; a tubular rotary part, said parts being positioned in endto-end relation with their confronting ends axially' aligned and spaced apart to form an adjacent exterior surface to form an annular packing receiving space in communication with said annular aperture; a packing within said packing space; and interior walls within said parts respectively forming fluid passageways of gradually decreasing diameter with their smallest diameters at. opposite sides of said annular aperture, the length of the second fluid passageway in said parts in the direction of flow of said fluid,

GUGLI'ELMO R. TREMOLADA.

' REFERENCES crrEn The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 794,499 Hageman July 11, 1905 1,617,776 Taylor Feb. 15, 1927 1,937,050 Tremolada .Nov. 28, 1933 2,176,323 Bowen et al. Oct. 7, 1939 2,237,715 Shaw et al. Apr. 8, 1941 2,459,472

Tremolada Jan; 18, 1949 

